Push the button to turn on power to the load (bulb).
When the power of the load drops below a preset value, the relay turns off and cuts power completely until the button is pressed again.
Intended to save power from sockets left on with chargers or other items plugged in. For example when a phone is unplugged from a charger, and the drawn power drops, the circtuit will turn off the socket automatically until the phone is plugged back in and the button pushed.
